Thanks Bluebee, I thought the spring tensioner would be the simplest and achieve my goal, and yes I am using motor and the controls from the treadmill, It cost me $25.00 for the treadmill and $50.00 for a machine shop to mill down the shaft to 1/2" and machine the hub that is set into the pulley on the extractor so $75.00 to make it happen, which is much cheaper then the $400.00 conversion kit from the manufacturer in Italy.